The surface to be plated of a composite made of a metallic and a non-metallic material is degreased and otherwise cleaned and immersed in a palladium activator fluid conditioned with a hydrogencarbonate to a pH of 2˜5. After this pretreating process, the composite is plated with a metal and becomes most suitable for use as a material for heat sink on hybrid ICs since it can be efficiently soldered and has better corrosion resistance.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A pretreating method before plating which comprises the steps of cleaning the surface of a composite of a metallic and a non-metallic material to be plated and performing a treatment for palladium activation with a palladium activator fluid at pH of 2-5.
2. The pretreating method according to claim 1 , wherein said composite is a material for a heat sink on a circuit board.
3. The pretreating method according to claim 1 or 2 , wherein the pH of said palladium activator fluid is adjusted with a hydrogencarbonate.
4. The pretreating method according to claim 1 or claim 2 , wherein said plate is applied by electroless plating.
5. The pretreating method according to claim 3 , wherein said plate is applied by electroless plating.
6. A composite of a metallic and a non-metallic material to which plating has been applied and the plated coat has a peel strength of at least 400 g in a wire-bond pull test with an aluminum wire as applied to said plated coat by ultrasonic bonding.
7. A composite of a metallic and a non-metallic material to which plating has been applied and the plated coat has a peel strength of at least 800 g in a wire-bond pull test with an aluminum wire as applied to said plated coat by ultrasonic bonding.
8. A composite of a metallic and a non-metallic material to which plating has been applied and the plated coat, if it is subjected to a wire-bond pull test with an aluminum wire as applied to it by ultrasonic bonding, has a failure mode which involves break either in the loop or at the neck of said aluminum wire.
9. The composite according to any one of claims 6 - 8 , wherein said plating is applied by electroless plating.
10. The composite according to claim 9 , wherein said plating is a Ni alloy plating.
11. The composite according to any one of claims 6 - 8 , wherein a main component of said metallic material is Al, Mg, Cu or Fe and a main component of said non-metallic material is SiC, Al 2 O 3 , AlN or Si 3 N 4 .
12. The composite according to claim 9 , wherein a main component of said metallic material is Al, Mg, Cu or Fe and a main component of said non-metallic material is SiC, Al 2 O 3 , AlN or Si 3 N 4 .
13. The composite according to claim 10 , wherein a main component of said metallic material is Al, Mg, Cu or Fe and a main component of said non-metallic material is SiC, Al 2 O 3 , AlN or Si 3 N 4 .
14. The composite according to any one of claims 6 - 8 , which is a material for a heat sink on a circuit board.
15. The composite according to claim 9 , which is a material for a heat sink on a circuit board.
16. The composite according to claim 10 , which is a material for a heat sink on a circuit board.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
March 27, 2003
May 18, 2004
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